Fully Integrated CTL Facility – The Block Diagram below provides an overview of the fully integrated coal to liquids (CTL) facility. This indirect coal liquefaction process is also referred to as the “engineered” approach. As the diagram illustrates, in addition to Fischer Tropsch fuels (diesel, jet fuel and naphtha), synthetic gas can also generate synthetic natural gas (SNG), hydrogen, ammonia, urea and electricity. The process can co-fire waste biomass and as can be seen, CO2 capture and use are very much a part of the process. The Fischer Tropsch gas to liquids (GTL) process is a set of catalyst assisted chemical reactions that convert a mixture of hydrogen and carbon monoxide (i.e. syngas) into liquid hydrocarbons (diesel, jet fuel and naphtha). The process was commercialized in Germany 1936 and further enhanced in South Africa where SASOL produces 160,000 bpd of synthetic fuel from coal.
Rapidly Expanding Industry – Coal gasification is a widely commercialized technology – ECUST, GE, Lurgi, Shell, Siemens …
According to Higman Consulting GmbH, in 2014 there were 272 gasification projects with 686 active commercial operating gasifiers in the world. The primary feedstock for the gasifiers is coal but the database also includes, biomass/waste, petroleum and petcoke as feedstock. More importantly, with the projects either under construction or approved, its envisioned that the number of operational gasifiers will exceed 1000 by 2018.
In North America and Europe the number of waste/biomass gasification to power facilities is increasing.
Poly-generational – Most of China’s gasification projects use coal to make chemicals (ammonia, urea), synthetic natural and synthetic fuels (FT liquids and methanol).
China Expansion – 20 coal conversion projects, including those which convert coal to diesel, synthetic natural gas, methanol, or olefin, were approved by the National Development and Reform Commission (NDRC) in 2013, with 4-5 scheduled to break ground before 2014 (FT May 1, 2013 Coal emerges as the Cinderella of China’s energy ball). Increasing Scale The scale of gasification projects in China is also on the increase, for example Sinopec, Huaneng Xinjiang Energy Development Co., Ltd. is investing $30 billion in a 90 million tons per year facility to produce 30 billion cubic meters (1 tcf per year) of synthetic gas which will be transported through pipelines to Zhejiang in east China and Guangdong in the south of the country. http://www.energychinaforum.com/news/75436.shtml To put this project in perspective, it consumes 90 million s. tons of coal per year which is 50X larger than the new 618 MWe IGCC in Edwardsport, Indiana, which consumes 1.7 – 1.9 million s. tons of coal per year. China’s success creates fast follower opportunities for Europe and North America.
Gasification – Gasification has been used worldwide on a commercial scale for making “town gas” from coal for heating, lighting and cooking for over 200 years. It has been used for more than 80 years by the chemical, refining and fertilizer industries to make hydrogen, ammonia and methanol, and for over 35 years by the electric power industry. Gasification is a thermal process that converts carbon based materials such as coal, waste, biomass or petcoke (feedstocks) into other forms of energy without actually burning it; it is not incineration. The process combines the carbon based feedstocks with limited amounts of air or oxygen, breaking them down into simple molecules, primarily a mixture of carbon monoxide and hydrogen (syngas). Gasification typically operates at temperatures ranging from 1450°F to 3000°F (Plasma gasification can generate temperatures up to 10,000°F (5,500ºC)). The gasification process can be completed in fixed bed, fluidized bed or plasma gasification configurations. The reactions that occur in a gasification process are: 1. C + O2 → CO2 2. C + H2O → CO + H2 3. C + CO2 → 2CO 4. C + 2H2 → CH4 5. CO + H2O → CO2 + H2 6. CO + 3H2 → CH4 + H2O The final product is a synthetic gas (syngas) that can be converted into transportation fuels, synthetic natural gas (SNG), fertilizers, electricity and other valuable products.
CTL Process Gasifier – In Envidity’s process; poor quality, low priced coal is fed into a gasifier with small amounts of oxygen supplied from an air separation unit (ASU). The synthetic gas produced contains H2, CO, CO2 and in some cases H2S. The by-product from the gasification process is fly ash which is used in the cement business and slag which is used in road construction. Note: if a plasma gasifier is used, then slag is the only by-product. Syngas Cleanup Proven commercial technologies from the oil and gas business are used to cleanup the synthetic gas, i.e. remove the CO2 and sulfur. The captured CO2 can either be stored in a deep saline aquifer, an abandoned oil & gas field, used for enhanced oil recovery (miscible gas flood) or converted into highly valuable end products such as methanol. Fischer-Tropsch (FT) Reactor Syngas with a 2:1 ratio of H2:CO is reacted with a cobalt catalyst in a Fischer–Tropsch reactor to produce a mixture of synthetic hydrocarbons, commonly referred to as synthetic crude oil or syncrude, a mixture of primarily straight-chain paraffins. The basic chemistry can be represented as: nCO + 2nH2 → CnH2n+2 + nH2O where n varies between 1 and greater than 30, with an average of 12. In Envidity’s case, FT wax is hydrocracked (upgraded) to generate diesel fuel and naphtha. Our diesel fuel is compatible with the existing oil industry infrastructure and the existing fleet of cars and trucks without any alterations. The fuel is ultra high quality and complies with the highest ecological requirements: zero aromatics, zero sulfur, zero nitrogen.