Sustainable production of bio-methanol by bio-methane and biogene CO2 gas from organic waste and residues

PROJECT DESCRIPTION

BACKGROUND

Glycerine (a colourless, odourless and non-toxic alcohol) is used in a wide range of applications in the medical, pharmaceutical, cosmetic and food industries. The production of bio-diesel has increased significantly in recent years, which has led to a surplus in its principle by-product, crude glycerine. Crude glycerine used to be a valuable commodity but because of this excess, it is now considered to be a low value by-product. Its quality is also variable and it has impurities that affect, and increase the operational costs of, industrial processes.

Crude glycerine is currently used to create methane, a more sustainable and cost efficient energy source than non-renewable fuels. The conversion of biogas is, however, inefficient (35 - 40% electrical efficiency, < 20% heat efficiency) and it is more valuable and sustainable to use crude glycerine to create biochemical products, such as methanol.

Methanol is usually derived from natural gas or other fossil carbon sources. Bio-methanol can, however, be produced using a combination of a thermochemical process (the gasification of high quality crude glycerine into synthesis gas) and conventional methanol synthesis. This method is chemically identical to conventional methanol production, but with up to 75% energy conversion efficiency and a reduction in fossil fuel use and greenhouse gas emissions.

However, currently, this thermochemical process can only be carried out using high quality crude glycerine. This means that crude glycerine must be purified before it is fed into the process. This generates residual waste, consumes a lot of energy and means that raw materials and residues have to be transported, ultimately leading to significant CO2 emissions and negative impacts on the environment.

OBJECTIVES

The LIFE SynSpirit project aimed at demonstrating a new anaerobic fermentation process through which organic waste streams and low quality crude glycerine are efficiently converted into high value bio-methanol. For the first time, the project would connect a biological anaerobic digestion process for crude glycerine with the sustainable thermochemical production of bio-methanol, based on high quality glycerine.

Expected results:

The efficient conversion of a low-value by-product into a valuable renewable product, helping to improve resource efficiency and CO2 emissions;

An industrial scale SynSpirit process, connected to an existing bio-methanol production process, installed and ready for operation;

A technically and economically viable SynSpirit process operating within the following performance indicators over a 12 month demonstration period: - A continuous and predictable mechanical and biological process; - The continuous production of biogas at the rate of 1300 - 1400 m3/hour from 12 000 tonnes of mixed quality crude glycerine, 12 000 tonnes of organic material and approximately 50 000 m3 of waste water; - High syngas injection availability (97%); - Chemical Oxygen Demand (COD) to biogas removal efficiency of >95%; - High hydrogen sulphide (H2S) removal efficiency; - Digestate (a product of anaerobic digestion)/waste water quality that meets the criteria of current waste water treatment plants; - The annual production of 13 750 tonnes of bio-methanol;

The production of technical evaluation and performance monitoring reports, including environmental and socio-economic indicators.

RESULTS

The project did not achieve results, as it terminated its grant agreement earlier.