@misc{9229850,
  abstract     = {{Raw biogas leaving an anaerobic digester is warm, saturated with water vapor, and contains small amounts of corrosive trace compounds. In this state, the gas cannot be fed directly to an upgrading system, where carbon dioxide, water vapor and other contaminants are removed to produce biomethane that meets a predefined quality. High humidity combined with reactive species promotes uncontrolled condensation and corrosion, making pre-cooling a necessary step to stabilize the gas before upgrading. The gas is therefore typically cooled in a shell-and-tube heat exchanger before entering downstream equipment. Designing such heat exchanger requires estimates of heat-transfer performance, condensation formation, outlet humidity, and pressure drop. This thesis develops a computational tool for the preliminary design of raw biogas coolers and evaluates its performance for representative operating conditions.

The modelling framework integrates thermodynamic property calculations, heat-transfer correlations, and pressure-drop formulations to determine required heat-transfer area and hydraulic behavior. Iterative solutions procedures are implemented to satisfy both thermal and hydraulic constraints. Representative design cases were defined based on typical raw biogas compositions, flow rates, cooling media, and temperature targets reported in industrial practice.

Due to limited availability of detailed geometric data of reference cases, the model is assessed though qualitative consistency checks rather than formal validation. The results exhibit physically reasonable trends for the estimated wet mass-flow rate, outlet relative humidity, condensate flow and required duty. Additionally, the tool successfully generated feasible designs for four unique design cases. The tool is therefore suitable for preliminary dimensioning and early-stage engineering assessments, while more advanced modelling and empirical data is required for a final design.

The thesis also includes a conceptual discussion of mounting orientation. Although the model cannot quantify orientation effects, literature indicates that horizontal and vertical configurations differ in condensate drainage, flow distribution, and fouling tendencies. Analysis of the heat exchanger lengths of the generated designs indicates that horizontal mounting is the most suitable.

Overall, the developed tool provides a transparent and useful basis for preliminary design of shell-and-tube raw biogas coolers and forms a foundation for future refinement and validation.}},
  author       = {{Johnsson, Evelina}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Tool for Preliminary Design of Shell-and-Tube Heat Exchangers for Biogas Upgrading}},
  year         = {{2026}},
}