Electrical Energy from gasification 190% higher than from AD

Environ Technol. 2014 Sep-Oct;35(17-20):2140-6.
Electrical energy production from biosolids: a comparative study between anaerobic digestion and ultra-high-temperature gasification. 
http://www.ncbi.nlm.nih.gov/pubmed/25145165
Abstract
Biosolids management is one of the most expensive and complicated processes in sanitation engineering. Anaerobic digestion (AD) is often employed for the stabilization of biomass and for energy production, as approximately 50% of the carbon entering the anaerobic digester is recovered as methane (CH4). Gasification has been used recently for the thermal reformation of biosolids to synthesis gas (syngas), which primarily consists of carbon monoxide (CO) and hydrogen (H2). In the present work, the net electrical energy production from biosolids has been calculated, for a typical activated sludge wastewater treatment plant, with an inlet flow rate of 75,708 m3/d (equal to 20 Mgd). The calculations suggest that the ultra-high-temperature gasification (UHTG) system can achieve a net electrical energy output of about 15.40 MJ/kg (dry biosolids), whereas the AD system can achieve values between 8.45 MJ/kg(dry biosolids). The latter values correspond to approximate net electrical energy power of 18.8 kW for UHTG, versus 9.9 kW for AD, for a wastewater treatment plant with capacity of 1000 m3/d; thus, the UHTG process yields approximately 190% of the energy that may be produced by the AD process. 

Extract of April 8th 2015 CALWMC presentation

Extract of April 8th 2015 CALWMC, my presentation

https://youtu.be/wl_XtQmenG8

Slide deck.
https://drive.google.com/…/0B1Kog53fI42ETFVzNHprUGpzN…/view…

Enjoy all those cost numbers getting smaller and smaller, while doing more for the environment!

This presentation was all about the residuals: how to manage the solids.  In the Seaterra plan the water is not reclaimed and must be sent out to the ocean via a long outfall. It also pumps the sludge 18km up to Hartland for digestion.  The capital costs of this are $300M.  The operating cost are offset by a small amount of revenue.  The process converts about 50% to energy and the remainder will be sent up island to be used "beneficially". This is code for spread on land.  In other words, pollute the forest which is a watershed.

The RITE plan advocates we consider tertiary water treatment which reclaims the water for use or to be discharged directly into the shore.  We also want to consider gasification that fully destroys the toxins in the sludge while producing nearly twice the energy output of digestion with a small amount of ask left over (useful in building products).
We contacted vendors and experts. One expert said he is working on a similar project that will cost under $15M US.   Gasification energy outputs are so high they make money from the start.  Reducing the capital costs by $315M; saving the huge interest payments on that debt; converting operating costs into revenue saves our region $2 Billion dollars over the lifetime of the project.

Replication of these results is quite simple.  

1. Perform a search of the internet for sewage sludge and gasification.
2. Contact the companies who are involved.
3. Ask them to suggest independent experts.
4. Ask them to tell you about similar projects.