Urban waste for biomethane grid injection and transport in urban areas

© ZAAO

City of Valmiera

Valmiera is a biggest city in the North Vidzeme region in Latvia. Approximately 30-40% of the total waste generated in the region is collected in Valmiera. Source separated waste collection system was introduced in the region in 2001. Today, the system offers collection for packaging (PET, glass, paper, cardboard etc.), bulky waste, construction waste, garden and park waste and Waste Electrical and Electronic Equipment (WEEE). There are 18 sorting stations (“ECO field”), 232 - packaging containers, and 163- PET containers in the region. In average, there are placed 8 containers per 1 km2 for source separate waste collection in populated areas.

Regarding bio-waste management the municipality of the Valmiera city approved (04.01.2012.) local binding regulations for waste management providing that legal persons such as catering services, shops, food processing companies and other entities that generate bio-waste must have a legal contract for source separate bio-waste collection services. Till now only 15 legal clients in Valmiera city have signed contracts for such a service with ZAAO, the waste management company in the region.

Currently, organic waste is not separated in the households, but collected together with municipal solid waste (MSW) and brought to the mechanical treatment facility in regional landfill “Daibe”.
The Waste Management Concept for Valmiera city, elaborated in the UrbanBiogas project, offers 2 scenarios for organic waste collection:

  • 1. Scenario (base scenario) – collection of unsorted MSW
  • 2. Scenario – collection of source separated organic waste.

In mid-term, the baseline scenario is preferred as the second scenario is currently economically not feasible. The introduction of the source separated organic waste collection has many obstacles: 1) lack of national-level regulatory framework, 2) waste management tariff increase for residents, 3) additional costs for waste management company for installation of separate organic waste collection bins and 4) increase in waste transportation costs.
Furthermore, for the organic waste treatment 3 scenarios were evaluated:

  • 1. Scenario (base scenario) – mechanical treatment of unsorted MSW at regional waste treatment centre located at Daibe landfill site by using the existing waste treatment infrastructure (MBT). Composting of the organic fraction and using the compost for daily cover of the landfill.
  • 2. Scenario – Mechanical treatment of unsorted MSW at regional waste treatment centre and using the organic fraction for dry fermentation. Digested substrate is further aerobically stabilised and used for daily cover of the landfill.
  • 3. Scenario – Source separated organic waste collection and treatment in wet Anaerobic Digestion plant.

In the mid-term, the 2nd scenario was selected as feasible in the given situation.
Calculations for biogas and biomethane production were based on the estimation that the total amount of organic waste generation in Valmiera and North Vidzeme region will increase from 9.86 thousand t in 2012 to 10.75 thousand t in 2020, and reaching 14.65 thousand t in 2030. Two scenarios were considered for biogas and biomethane production:

  • 1. Combined scenario – unsorted MSW collection, mechanical treatment at Daibe landfill site, dry fermentation of organic fraction, use of biogas in existing CHP plant and use of biogas for upgrading starting from 2020. Digestate would be used for the daily cover of the landfill.
  • 2. Resource-efficiency scenario – source separated organic waste collection from households from 2017, wet AD, use of biogas in existing CHP plant and use of biogas for upgrading starting from 2020. Digestate would be used as high quality fertilizer.

In a mid-term the combined scenario was selected as economically most feasible.
During the UrbanBiogas project a concept for the use of biomethane was developed as provisional future opportunity. Biogas upgrading and biomethane use under existing framework conditions is not economically feasible. Biomethane production (biogas upgrading and compression) and use is evaluated in a perspective starting from 2020. Three alternatives for biomethane use were considered:

  • Biomethane use as fuel for waste collection trucks of ZAAO
  • Biomethane use as fuel for public busses in Valmiera city
  • Biomethane use in public filling stations for private transport and municipality transport

From all these 3 alternatives the biomethane use in ZAAO waste collection trucks and setting-up a biomethane filling station next to the biogas upgrading plant at Daibe landfill site was proposed as most feasible. In order to be able to use biomethane for public busses, the long term planning is required. The city should plan in future a procurement of CNG busses and construct appropriate biomethane transportation and filling infrastructure.
Three potential locations of the new WtB plant were evaluated: (1) biogas/biomethane plant at Daibe landfill site, (2) new biogas plant in the vicinity of Valmiera city, and (3) delivery of collected organic waste to one of existing biogas plants near Valmiera. Since for the mid-term the combined scenario was selected and it is foreseen to use the existing waste collection system and infrastructure of Daibe waste management centre, the biogas upgrading facility also should be located at Daibe landfill site. Besides availability of the infrastructure this location has other benefits, e.g., distance from residential areas and therefore the public acceptance for this alternative is expected to be positive.
The following organisational model was selected for the implementation of WtB project in Valmiera: collection of unsorted municipal solid waste, mechanical treatment at “Daibe” landfill site (owned by ZAAO), using organic fraction of the waste for dry fermentation. Biogas will be used for CHP and after 2020 – upgraded to biomethane and used for transport or injected into the natural gas grid.

The main investor that is foreseen in the current organisational model is ZAAO Ltd. ZAAO has started the first steps in order to make an investment. In the end of 2013 ZAAO has applied a project application for EU Cohesion Fund programme and have got approval for construction of anaerobic digestion dry fermentation plant. The technical specification of the project has been prepared and the call for applications for potential technology providers was announced. Unfortunately by the end of April 2014 the tender for construction works was cancelled because of external risks analysis results: mainly risks for project realisation time frame and raw material long term supply security. Currently the implementation of the project is postponed.

Reports about Valmiera

  • Waste Management Concept for Valmiera City EN
  • Biogas & Biomethane Production in Valmiera, Latvia EN
  • Economic Feasibility of WtB Concepts for Valmiera, Zagreb and Graz EN
  • Biomethane use for cities: grid injection & transport in Valmiera/Latvia EN
  • Report on the event in Latvia for stimulating competition among biogas plant planners and companies EN
  • Report on the national expert consultation meeting on biomethane use in Latvia EN

 

  • Aptaujas „Atkritumu apsaimniekošanas un škirošanas sistemas novertešanai Valmiera” rezultati LV
  • Biometana izmantošanas koncepcija Valmieras pilsetai LV
  • Biogazes un biometana ražošanas koncepcija Valmieras pilsetai LV
  • Report on the public consultation, including the results of the survey in Valmiera, Latvia EN, LV

 

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North Vidzeme Waste Management Company
Latvia

Contact: Martinš Niklass
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +371 29146130
Website: www.zaao.lv

EKODOMALatvia

Contact: Ilze Dzene
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Phone: +371 67323212
Website: www.ekodoma.lv

© WIP - Renewable Energies • Sylvensteinstr. 2 • D - 81369 Munich, Germany • 2011