Bioenergy with Carbon Capture and Storage: Role in Climate Mitigation

With increasing concern and awareness of climate change, there has been a growth in the renewable energy sector through government subsidies and private investment, allowing for the replacement of current sources of energy with less carbon-intensive fuels. However, renewable energy technologies are yet to topple the traditional fossil fuel-powered electricity market. With the increasing trajectory of global emissions, climate research has been exploring other methods of climate mitigation, for instance, through the use of large-scale geoengineering technologies.

Biomass-Resources

A quick glance at popular biomass resources

Of particular focus are the carbon dioxide removal techniques, namely Carbon Capture and Storage (CCS) and Bioenergy with Carbon Capture and Storage (BECCS) that have been prominently featured in emission scenarios of climate models, particularly for their direct influence in reducing carbon dioxide emissions.

CCS involves capturing carbon dioxide emissions from industries and storing them under geological reservoirs either on shore or offshore. You can read more about this technology on a previous EcoMENA article.

What is Bioenergy with Carbon Capture and Storage

One of the main concerns about CCS is the use of fossil fuels for its operations. In the pursuit for greener climate mitigation technologies, Bioenergy with Carbon Capture and Storage (BECCS) has emerged as a climate saviour, featuring in prominent emissions scenarios and climate models to achieve the 1.5-degree target.

In the place of fossil fuels, biomass is instead used as the primary fuel source for BECCS as seen in the picture below. The two-step absorption of carbon dioxide, first during the growth of the biomass, and second through capturing of the biomass emissions, makes BECCS, in theory, a net negative emissions technique.

Source: Can we deploy enough BECCS to achieve climate targets? AVOID 2

Of the 116 climate scenarios suggested by the IPCC, BECCS was seen to have a significant role in 101 of the scenarios to help prevent global temperature rise above the 1.5-degree target. In fact, UK electricity generator Drax, has chosen to invest in the BECCS technology and started its first trial earlier this year, making it the first of its kind in Europe.

Risks associated with BECCS

While the combination of bioenergy and CCS provides an ideal carbon negative mitigation strategy, it also combines the existing risks associated with both technologies. In addition to lack of investment and long-term economic policies for CCS, large scale deployment of BECCS is hindered by uncertainties such as land, water and resource availability. Studies have shown concerns regarding the carbon intensity and the scale of land and resources required to sustain the bioenergy component required for BECCS.

While the net negative aspect of BECCS may work in theory, studies have revealed significant proportions of emissions associated with indirect land use change for biomass production for BECCS. In addition to technical challenges, one of the key constraints for the deployment of such climate technologies is social acceptance, where sections of the general public, or specific stakeholders, remain unconvinced with certain aspects of the technology due to ethical or political reasons.

Conclusion

As such, while CCS and BECCS may offer the ideal climate saviour solution to reduce overall carbon dioxide emissions, the technologies are still overcast with various technical and social challenges that limit their commercial usage for climate mitigation.

Biomass Energy in China

Biomass energy in China has been developing at a rapid pace. The installed biomass power generation capacity in China increased sharply from 1.4 GW in 2006 to 14.88 GW in 2017. While the energy share of biomass remains relatively low compared to other sources of renewable energy, China plans to increase the proportion of biomass energy up to 15 percent and total installed capacity of biomass power generation to 30 GW by 2030.

biomass-china

In terms of impact, the theoretical biomass energy resource in China is about 5 billion tons coal equivalent, which equals 4 times of all energy consumption. As per conservative estimates, currently China is only using 5 percent of its total biomass potential.

According to IRENA, the majority of biomass capacity is in Eastern China, with the coastal province of Shandong accounting for 14 percent of the total alone. While the direct burning of mass for heat remains the primary use of biomass in China, in 2009, composition of China’s biomass power generation consisted in 62 percent of straw direct-fired power generation and 29 percent of waste incineration, with a mix of other feedstock accounting for the remaining 9 percent.

Biomass Resources in China

Major biomass resources in China include waste from agriculture, forestry, industries, animal manure and sewage, and municipal solid waste. While the largest contributing sources are estimated to be residues from annual crop production like wheat straw, much of the straw and stalk are presently used for cooking and heating in rural households at low efficiencies. Therefore, agricultural residues, forestry residues, and garden waste were found to be the most cited resources with big potential for energy production in China.

Agricultural residues are derived from agriculture harvesting such as maize, rice and cotton stalks, wheat straw and husks, and are most available in Central and northeastern China where most of the large stalk and straw potential is located. Because straw and stalks are produced as by-products of food production systems, they are perceived to be sustainable sources of biomass for energy that do not threaten food security.

Furthermore, it is estimated that China produces around 700 Mt of straw per year, 37 percent of which is corn straw, 28 percent rice, 20 percent wheat and 15 percent from various other crops. Around 50 percent of this straw is used for fertilizers, for which 350 Mt of straw is available for energy production per year.

Biomass resources are underutilized across China

Biomass resources are underutilized across China

Forestry residues are mostly available in the southern and central parts of China. While a few projects that use forestry wastes like tree bark and wood processing wastes are under way, one of the most cited resources with analyzed potential is garden waste. According to research, energy production from garden waste biomass accounted for 20.7 percent of China’s urban residential electricity consumption, or 12.6 percent of China’s transport gasoline demand in 2008.

Future Perspectives

The Chinese government believes that biomass feedstock should neither compete with edible food crops nor cause carbon debt or negative environmental impacts. As biomass takes on an increasing significant role in the China’s national energy-mix, future research specific to technology assessment, in addition to data collection and supply chain management of potential resources is necessary to continue to understand how biomass can become a game-changer in China’s energy future.

References

IRENA, 2014. Renewable Energy Prospects: China, REmap 2030 analysis. IRENA, Abu Dhabi. www.irena.org/remap

National Academy of Engineering and NRC, 2007: Energy Futures and Urban Air Pollution: Challenges for China and the United States.

Xingang, Z., Zhongfu, T., Pingkuo, L, 2013. Development goal of 30 GW for China’s biomass power generation: Will it be achieved? Renewable and Sustainable Energy Reviews, Volume 25, September 2013, 310–317.

Xingang, Z., Jieyu, W., Xiaomeng, L., Tiantian, F., Pingkuo, L, 2012. Focus on situation and policies for biomass power generation in China. Renewable and Sustainable Energy Reviews, Volume 16, Issue 6, August 2012, 3722–3729.

Li, J., Jinming, B. MOA/DOE Project Expert Team, 1998. Assessment of Biomass Resource Availability in China. China Environmental Science Press, Beijing, China.

Klimowicz, G., 2014. “China’s big plans for biomass,” Eco-Business, Global Biomass Series, accessed on Apr 6, 2015.

Shi, Y., Ge, Y., Chang, J., Shao, H., and Tang, Y., 2013. Garden waste biomass for renewable and sustainable energy production in China: Potential, challenges and development. Renewable and Sustainable Energy Reviews 22 (2013) 432–437

Xu, J. and Yuan, Z, 2015. “An overview of the biomass energy policy in China,” BESustainable, May 21, 2015.

The Importance of Biomass Energy in Energy Mix

Biomass energy has rapidly become a vital part of the global renewable energy mix and account for an ever-growing share of electric capacity added worldwide. Renewable energy supplies around one-fifth of the final energy consumption worldwide, counting traditional biomass, large hydropower, and “new” renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels).

Traditional biomass, primarily for cooking and heating, represents about 13 percent and is growing slowly or even declining in some regions as biomass is used more efficiently or replaced by alternative energy forms. Some of the recent predictions suggest that biomass energy is likely to make up one third of the total world energy mix by 2050. Infact, biofuel provides around 3% of the world’s fuel for transport.

biomass_feedstock

Biomass energy resources are readily available in rural and urban areas of all countries. Biomass-based industries can foster rural development, provide employment opportunities and promote biomass re-growth through sustainable land management practices.

The negative aspects of traditional biomass utilization in developing countries can be mitigated by promotion of modern waste-to-energy technologies which provide solid, liquid and gaseous fuels as well as electricity. Biomass wastes encompass a wide array of materials derived from agricultural, agro-industrial, and timber residues, as well as municipal and industrial wastes.

The most common technique for producing both heat and electrical energy from biomass wastes is direct combustion. Thermal efficiencies as high as 80 – 90% can be achieved by advanced gasification technology with greatly reduced atmospheric emissions.

Combined heat and power (CHP) systems, ranging from small-scale technology to large grid-connected facilities, provide significantly higher efficiencies than systems that only generate electricity. Biochemical processes, like anaerobic digestion and sanitary landfills, can also produce clean energy in the form of biogas and producer gas which can be converted to power and heat using a gas engine.

Advantages of Biomass Energy

Biomass energy systems offer significant possibilities for reducing greenhouse gas emissions due to their immense potential to replace fossil fuels in energy production. Biomass reduces emissions and enhances carbon sequestration since short-rotation crops or forests established on abandoned agricultural land accumulate carbon in the soil.

Bioenergy usually provides an irreversible mitigation effect by reducing carbon dioxide at source, but it may emit more carbon per unit of energy than fossil fuels unless biomass fuels are produced unsustainably.

Biomass can play a major role in reducing the reliance on fossil fuels by making use of thermochemical conversion technologies. In addition, the increased utilization of biomass-based fuels will be instrumental in safeguarding the environment, generation of new job opportunities, sustainable development and health improvements in rural areas.

The development of efficient biomass handling technology, improvement of agro-forestry systems and establishment of small and large-scale biomass-based power plants can play a major role in rural development and sustainable utilization of biomass. Biomass energy could also aid in modernizing the agricultural economy.

Consistent and reliable supply of biomass is crucial for any biomass project

When compared with wind and solar energy, biomass power plants are able to provide crucial, reliable baseload generation. Biomass plants provide fuel diversity, which protects communities from volatile fossil fuels. Since biomass energy uses domestically-produced fuels, biomass power greatly reduces our dependence on foreign energy sources and increases national energy security.

A large amount of energy is expended in the cultivation and processing of crops like sugarcane, coconut, and rice which can met by utilizing energy-rich residues for electricity production.

The integration of biomass-fueled gasifiers in coal-fired power stations would be advantageous in terms of improved flexibility in response to fluctuations in biomass availability and lower investment costs. The growth of the bioenergy industry can also be achieved by laying more stress on green power marketing.

Bioenergy in Southeast Asia: Perspectives

Southeast Asia, with its abundant bioenergy resources, holds a strategic position in the global biomass energy atlas. There is immense biomass energy potential in Southeast Asian countries due to plentiful supply of diverse forms of biomass wastes, such as agricultural residues, woody biomass, animal wastes, municipal solid waste, etc. The rapid economic growth and industrialization in the region has accelerated the drive to implement the latest waste-to-energy technologies to tap the unharnessed potential of biomass resources.

Southeast_asia

Southeast Asia is a big producer of agricultural and wood products which, when processed in industries, produces large amounts of biomass residues. According to conservative estimates, the amount of biomass residues generated from sugar, rice and palm oil mills is more than 200-230 million tons per year which corresponds to cogeneration potential of 16-19 GW.

Rice mills in the region produce 38 million tonnes of rice husk as solid residue which is a good fuel for producing heat and power. Sugar industry is an integral part of the industrial scenario in Southeast Asia accounting for 7% of sugar production worldwide. Sugar mills in Thailand, Indonesia, Philippines and Vietnam generate 34 million tonnes of bagasse every year.  Malaysia, Indonesia and Thailand account for 90% of global palm oil production leading to the generation of 27 million tonnes of waste per annum in the form of empty fruit bunches (EFBs), fibers and shells, as well as liquid effluent.

Woody biomass is a good energy resource due to presence of large number of forests in Southeast Asia. Apart from natural forests, non-industrial plantations of different types (e.g. coconut, rubber and oil palm plantations, fruit orchards, and trees in homesteads and gardens) have gained recognition as important sources of biomass. In addition, the presence of a large number of wood processing industries also generates significant quantity of wood wastes. The annual production of wood wastes in the region is estimated to be more than 30 million m3.

The prospects of biogas power generation are also high in the region, thanks to presence of well-established food-processing and dairy industries. Another important biomass resource is contributed by municipal solid wastes in heavily populated urban areas.  In addition, there are increasing efforts both commercially and promoted by governments to develop biomass energy systems for efficient biofuel production, e.g. bio-diesel from palm oil.

Biomass resources, particularly residues from forests, wood processing, agricultural crops and agro-processing, are under-utilised in Southeast Asian countries. There is an urgent need to utilize biomass wastes for commercial electricity and heat production to cater to the needs of the industries as well as urban and rural communities.

Southeast Asian countries are yet to make optimum use of the additional power generation potential from biomass waste resources which could help them to partially overcome the long-term problem of energy supply. Technologies for biomass utilization which are at present widely used in Southeast counties need to be improved towards best practice by making use of the latest trends in the biomass energy sector.